Re: [PATCH] dynahash: add memory allocation failure check - Mailing list pgsql-hackers

From Andrey Borodin
Subject Re: [PATCH] dynahash: add memory allocation failure check
Date
Msg-id BC159F74-1862-4B3A-9D31-29BF408F58A4@yandex-team.ru
Whole thread Raw
In response to [PATCH] dynahash: add memory allocation failure check  (m.korotkov@postgrespro.ru)
Responses Re: [PATCH] dynahash: add memory allocation failure check
List pgsql-hackers

> On 23 Apr 2025, at 13:32, m.korotkov@postgrespro.ru wrote:
>
> I found a case of potential NULL pointer dereference.
> In src/backend/utils/hash/dynahash.c in function HTAB *hash_create() the result of the DynaHashAlloc() is used
unsafely.
> The function DynaHashAlloc() calls MemoryContextAllocExtended() with MCXT_ALLOC_NO_OOM and can return a NULL pointer.
> Added the pointer check for avoiding a potential problem.

Yeah, good catch.
And all HTAB->alloc() (which relies on DynaHashAlloc) callers seem to check for NULL result.
It seems there are a lot of cases of MCXT_ALLOC_NO_OOM, perhaps should we check them all?


Best regards, Andrey Borodin.


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